1. Field of the Invention
The present invention relates to a camera with a data photographing device which selectively photographs plural kinds of data each comprising plural digits of numerals and/or characters, such as "year/month/day" and "hour/minute", on respective frames of a film in sequence when exposed for taking shots.
2. Related Background Art
In data photographing devices of commercially available cameras, it is conventional that when a data photographing mode is selected, data of "year/month/day" or "hour/minute" selected in advance by a photographer is read from an electronic clock including a clock pulse source such as a crystal oscillator, and then photographed on a film when exposed for taking shots. This permits the data of "year/month/day" or "hour/minute" to be indicated by numerical values on each of photoprints, so that the shooting data or time can be confirmed upon those photoprints being looked at later. Using that data makes it easy to rearrange or put in order the photoprints.
There are so far known two types of data photographing devices for commercially available cameras. One type device includes a data photographing unit which comprises liquid crystal indicator elements or the like able to indicate the data such as "year/month/day" all together, whereby the data is photographed on a film at a time while the film is at the same rest for taking a shot. The other type device includes a plurality of light emitting elements arrayed into a line perpendicular to the feeding direction of a film, those light emitting elements being so controlled synchronously with feeding of the film as to photograph the data on the film being fed.
The former type device requires only control of the indicator elements, and hence has an advantage of simplified construction of the device. However, restrictions on the number of digits for numerals and/or characters which can be indicated by the data photographing unit, necessarily reduce an amount of data capable of being photographed at the same time. For example, it is therefore impossible to photograph both "year/month/day" and "hour/minute" simultaneously. Usually, either kind of data is selected by a photographer to be photographed.
The latter type device enables the whole of each frame of a film to be employed as a data photographing region, thereby allowing simultaneous insertion of both "year/month/day" and "hour/minute". However, since the light emitting elements have to be controlled synchronously with feeding of the film, the device requires an encoder for precisely sensing a fed amount of the film and a circuit for converting the photographed data to dot line data, thus resulting in complicated construction and the increased cost of the device.
Related Japanese and United States Patent Applications are as follows.
Japanese utility Model Laid-Open No. 50(1975)-151229 discloses a technique of photographing plural characters on each frame of a film with constant spacings between those characters, by using a single light emitting element capable of indicating one digit (one character) which is energized to cyclically emit light, while feeding the film at a constant speed. Also described in that Japanese Utility Model Laid-Open Publication is "the film may be stopped in synchronous relation whenever the light emitting element is energized to emit light". But, the above Japanese utility Model Laid-Open Publication illustrates only the film, the light emitting element, and a lens disposed between the former two, but does not particularly refer to a manner in which feeding of the film and light emission from the light emitting element are to be controlled.
U.S. Pat. No. 4,198,146 discloses two types of data photographing devices. The first type device has a photographing unit able to selectively indicate the data of "year/month/day" or "month/day/hour/minute" in one lot, so that preselected data either of "year/month/day" or "month/day/hour/minute" may be photographed on each frame of a film at a predetermined position by using the photographing unit. Thus, the data photographing device of the first type disclosed in that U.S. Patent cannot photograph two kinds of data on the same frame of the film.
The second type device has a photographing unit able to selectively indicate the data of "month/day", "year" or "hour/minute" in one lot. After indicating the data of "month/day" in the photographing device to photograph that data on one frame of a film at a first position, a rotatable mirror disposed between the photographing device and the film is driven to change an optical path of data extending from the photographing unit. Then, by indicating data either of "year" or "hour/minute" in the photographing device, that data is photographed on the same frame of the film at a second position (different from the first position) Which one of "year" or "hour/minute" is to be photographed after the data of "month/day" is selected in advance by actuating a selector switch. This data photographing device of the second type can photograph two kinds of data on the same frame of the film by the single photographing unit. In return for that capability, however, it requires the rotatable mirror for changing the optical path of data and a driver for rotating the mirror. Thus, the camera mounting thereon the data photographing device of the second type is increased in its overall size. Further, the data photographing device of the second type makes it possible to always photograph two kinds of data on the same frame, but not to photograph one kind of data alone. In addition, whenever the data is photographed, the mirror has to be driven for photographing the second data ("year" or "hour/minute"). Feeding of the film to be ready for the next shot cannot be started until the second data has completely been photographed after driving the mirror. This prolongs a period of time required for preparing the next shot.
Japanese Patent Laid-Open No. 54(1979)-101314 discloses three types of data photographing devices. The first type device is similar to the data photographing device of the first type as disclosed in the above U.S. Pat. No. 4,198,146 as to selectively photographing the data of "year/month/day" or "hour/minute/second" (by selecting either one of them). This first type device cannot photograph two kinds of data on the same frame of a film.
The second type device is able to photograph both the data of "hour/minute/second" and "year/month/day" on the same frame of the film in order by using a single data photographing unit. With this second type device, in interlock relation with a depressed stroke of a release button to release a shutter, the data of "hour/minute/second" is indicated in the data photographing unit for being photographed on one frame of the film at a first position. Then, a lens supported between the data photographing unit and the film in a manner to pivot is swung in interlock relation with a return stroke of the release button, so that the data of "year/month/day" is photographed on the same frame of the film at a second position. As with the above prior art, although this data photographing device of the second type can photograph two kinds of data on the same frame of the film by the single photographing unit, it requires the lens for changing an optical path of data and a driver for swinging the lens. Thus, the camera mounting thereon this data photographing device of the second type is increased in its overall size. Further, this data photographing device of the second type also makes it possible to always photograph two kinds of data on the same frame, but not to photograph one kind of data alone. In addition, the need of swinging the lens to change over the optical path of data upon the reciprocal movement of the release button in turn requires increasing the movement stroke of the release button. Another problem in this second type device is as follows. The depressed position of the release button enough to photograph the first data (i.e., data of "hour/minute/second") is shallower than the depressed position of the release button enough to release the shutter. Therefore, if a photographer's finger is detached from the release button immediately after photographing of the data of "hour/minute/second", the shutter is left not released and, that is, exposure for taking a shot remains not triggered, thereby resulting in a frame of the film on which only the data of "hour/minute/second" has been photographed. Repeating the above process would photograph different data of "hour/minute/second" on the same frame in overlapped relation.
The third type device is also able to photograph both the data of "hour/minute/second" and "year/month/day". on the same frame of the film in order by using a single data photographing unit. But it is different from the second type device in that both the data are photographed in order while feeding a cut-sheet like film from its container. More specifically, the third type device has a claw which is movable straight-forward to feed the film out of the container after photo-taking a picture. The claw is provided with two projections spaced from each other in the direction of movement of the claw. During the moving process, these projections successively strike against a switch adapted to specify the timing of data photographing. In an initial stage just after the claw starts moving, the first projection strikes against the switch to turn it on, whereby the data of "hour/minute/second" is photographed on the film at a first position. Afterward, the claw continues to move without stopping and the second projection now strikes against the switch to turn it on, whereby the data of "year/month/day" is photographed on the film at a second position. Even after that, the claw still continues to move for discharging the film out of the container. This data photographing device of the third type also makes it possible to always photograph two kinds of data on the same frame, but not to photograph one kind of data alone. Further, since the two kinds of data are photographed while moving the film, it is required to lower a feed speed of the film or to increase the intensity of light emitted from the data photographing unit thereby to shorten a data photographing time, for ensuring clearness of the photographed data. Moreover, the successive photographing of the two kinds of data additionally needs to provide the two projections and the switch turned on by the projections, whereby the construction is more complicated.
Regarding data photographing devices among the known various data photographing devices as mentioned above which successively photograph the two kinds of data, variable with the elapse of time, on the same frame of the film, there is a fear that the photographed data may be largely different from the actual time point of taking the shot, because of some time interval between the time point of reading the first photographed data from the electronic clock and the time point of reading the second photographed data from the electronic clock, if those time points of reading the first and second data are just set apart from each other across the turn of a year, month, day or hour. For example, assuming in the device of successively photographing the two data of "month/day" and "year" or the two data of "month/day" and "hour/minute" as disclosed in the above U.S. Pat. No. 4,198,146 that the first data of "month/day" is read from the electronic clock at the time point of 23:59:59 on Dec. 31, 1989 and the second data of "year" or " hour/minute" is read from the electronic clock at the time point of 0:0:0 on Jan. 1, 1990, the data of "month/day", "year" and "hour/minute" would be "12 31", "90" and "0, 0", respectively. Accordingly, if the data of "month/day" and "year" are photographed successively, there would occur a shift of a whole year from the actual time point of taking the shot. If the data of "month/day" and "hour/minute" are photographed successively, there would occur a shift of a whole day, i.e., 24 hours, from the actual time point of taking the shot. A similar problem is encountered in the above device of Japanese Patent Laid-Open No. 54(1979)-101314 as well.